@Gijs Hello, I found the "transfer" button on the original owner "Device" interface. But as he deleted it, the device is viewable in "Deleted Device" not in "Device" and there is no such a transfer button for Deleted Device. I tried with the Deleted Device PAC and get : "CRA rejected the modem ownership transfer: The device with id 00000000 can't be registered for the moment, please contact your device vendor.". (note the strange 00000000 instead of the PAC i gave) Another strange thing : the Deleted Device PAC is "E9--------------" (with - not to write the real one :-)) while the ubinascii.hexlify(Sigfox().pac()) gives "82--------------" maybe the issue is there? Any idea?